title: Autoantibody to interferon-gamma associated with adult-onset immunodeficiency in non-HIV individuals in Northern Thailand.
abstract: BACKGROUND
  Autoantibody to interferon-gamma (IFN-γ) has been reported to be associated with adult-onset immunodeficiency in patients from Asian countries. This study aimed to determine the prevalence of autoantibody to IFN-γ among non-HIV patients in northern Thailand who were repeatedly infected with unusual intracellular pathogens.
  
  
  METHODS
  A cross-sectional, case-control study was conducted between March 2011 and March 2012 at Chiang Mai University Hospital. 20 cases, non-HIV, aged 18-60 years, presented with at least 2 episodes of culture or histopathology proven opportunistic infections were enrolled. Controls comprised 20 HIV-infected patients and 20 healthy adults who were age- and sex-matched with cases. Enzyme-linked immunosorbent assay (ELISA) was used to detect the presence of antibody to IFN-γ.
  
  
  RESULTS
  11 participants in each group were female. The mean ages were 48.1±6.4, 48.3±6.3, and 47.1±6.5 years among cases, HIV-infected, and healthy controls, respectively. The opportunistic infections among 20 cases included disseminated non-tuberculous mycobacterial (NTM) infection (19 patients/24 episodes), disseminated penicilliosis marneffei (12 patients/12 episodes), and non-typhoidal Salmonella bacteremia (7 patients/8 episodes). At the cutoff level of 99 percentile of controls, the prevalence of autoantibody to IFN-γ were 100%, 0%, and 0%, among cases, HIV-infected, and healthy controls, respectively (p-value <0.001). The mean concentrations of antibody to IFN-γ were 3.279±0.662 and 0.939±0.630 O.D. among cases with and without active opportunistic infection, respectively (p-value<0.001).
  
  
  CONCLUSIONS
  In northern Thailand, autoantibody to IFN-γ was strongly associated with adult-onset immunodeficiency. The level of antibody to IFN-γ in patients who had active opportunistic infection was relatively higher than those without active infection.
authors.affiliation: Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Panuwat
authors.initials: P
authors.lastname: Wongkulab
authors.forename: Jiraprapa
authors.initials: J
authors.lastname: Wipasa
authors.forename: Romanee
authors.initials: R
authors.lastname: Chaiwarith
authors.forename: Khuanchai
authors.initials: K
authors.lastname: Supparatpinyo
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology* / Q000302:isolation & purification; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000276:immunology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000453:epidemiology* / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000150:complications; D009181:Mycoses / Q000150:complications; D009894:Opportunistic Infections / Q000150:complications; D012480:Salmonella Infections / Q000150:complications; D013785:Thailand
chemical_list: D001323:Autoantibodies; D007371:Interferon-gamma